From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrea Arcangeli Subject: Re: [patch 2/4] mmu_notifier: Callbacks to invalidate address ranges Date: Sun, 3 Feb 2008 03:23:56 +0100 Message-ID: <20080203022356.GD7185@v2.random> References: <20080201050439.009441434@sgi.com> <20080201050623.344041545@sgi.com> <20080201220952.GA3875@sgi.com> <20080201233528.GE12099@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Peter Zijlstra , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, steiner-sJ/iWh9BUns@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Avi Kivity , kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, daniel.blueman-xqY44rlHlBpWk0Htik3J/w@public.gmane.org, Christoph Lameter To: Robin Holt Return-path: Content-Disposition: inline In-Reply-To: <20080201233528.GE12099-sJ/iWh9BUns@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org On Fri, Feb 01, 2008 at 05:35:28PM -0600, Robin Holt wrote: > No, we need a callout when we are becoming more restrictive, but not > when becoming more permissive. I would have to guess that is the case > for any of these callouts. It is for both GRU and XPMEM. I would > expect the same is true for KVM, but would like a ruling from Andrea on > that. I still hope I don't need to take any lock in _range_start and that losing coherency (w/o risking global memory corruption but only risking temporary userland data corruption thanks to the page pin) is ok for KVM. If I would have to take a lock in _range_start like XPMEM is forced to do (GRU is by far not forced to it, if it would switch to my #v5) then it would be a problem. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/